Role of proteoglycan sulfation during muscle regeneration in dystrophic animals

蛋白多糖硫酸化在营养不良动物肌肉再生过程中的作用

基本信息

批准号：
9066087
负责人：
Matthew Tierney
金额：
$ 0.95万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-06-01 至 2016-09-23
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9066087
关键词：
Adult Animals Behavior Behavioral Binding Biological Assay Biological Availability Cells Communication Complex Cues Development Disease Progression Donor person Duchenne muscular dystrophy Environment Event Exhibits FGF2 gene Fetal Tissues Fibroblast Growth Factor Fibroblast Growth Factor Receptors Fluorescence-Activated Cell Sorting Gene Expression Goals Growth Health Heparan Sulfate Proteoglycan Impairment In Vitro Intervention Ligands Measures Mediating Mediator of activation protein Membrane Mitogens Molecular Monitor Mus Muscle Muscle satellite cell Muscular Atrophy Natural regeneration Pathway interactions Patients Pattern Phosphorylation Play Post-Translational Protein Processing Pre-Clinical Model Proteoglycan Quality of life Regulation Resistance Role Signal Pathway Signal Transduction Signaling Molecule Skeletal Muscle Staging Stem cells Sulfatases Testing Therapeutic Effect Transplantation Wasting Syndrome Western Blotting Work beta catenin bioluminescence imaging cell behavior extracellular fetal functional disability human disease improved in vivo innovation insight mouse model muscle regeneration myogenesis neutralizing antibody new therapeutic target pre-clinical prospective receptor regenerative repaired response self-renewal sulfation syndecan therapy design tool

项目摘要

DESCRIPTION (provided by applicant): Muscle stem cells (MuSC) are required for the development and repair of skeletal muscle. During these dynamic periods of muscle growth and regeneration, MuSC must selectively interpret a host of signaling molecules to self-renew. This ability is progressively impaired in Duchenne muscular dystrophy (DMD), a devastating muscle wasting disease for which there is no cure. DMD is characterized by altered microenvironmental signaling that negatively influences MuSC-mediated regenerative potential. To better understand how MuSC communicate with their extracellular environment, I explored several membrane-bound mediators of signal transduction. Heparan sulfate proteoglycans (HSPG), in particular syndecans, are highly expressed in MuSC and can regulate ligand bioavailability and receptor formation. Heterogeneous sulfation patterns on HSPG via post-translational modifications increase behavioral complexity, leading to a differential activity of critical signalng pathways. Because regeneration in the adult recapitulates several aspects of myogenesis, I focused my preliminary studies on HSPG sulfation in fetal MuSC, the developmental precursors of adult MuSC. I have demonstrated that Sulf1, a specific regulator of HSPG 6-O-sulfation, is downregulated in fetal MuSC. I provide evidence that fetal MuSC are resistant to myogenic commitment in vitro and capable of rapid in vivo expansion and long-term self-renewal following transplantation. Furthermore, uncommitted fetal MuSC are preferentially sensitive to the potent mitogen FGF2 while less responsive to Wnt/β-catenin-mediated myogenic differentiation. Indeed, Sulf1 has been previously shown to simultaneously promote Wnt/β-catenin and inhibit FGF2 signaling. Sulf1 and HSPG expression are dysregulated in muscle wasting conditions. Therefore, the goal of this project is to examine the role of HSPG 6-O-sulfation on the regulation of dystrophic MuSC self-renewal and regenerative potential. To accomplish this, I propose (Aim 1a) to validate HSPG sulfatase and FGF and Wnt/β-catenin signaling component expression levels throughout myogenesis and in dystrophic animals. To determine MuSC responsiveness to FGF and Wnt/β-catenin pathway activation (Aim 1b), I will measure the expression and phosphorylation levels of downstream signaling pathway effectors. Inhibition of HSPG 6-O-sulfation will ascertain its role in FGF receptor complex formation and Wnt3a ligand bioavailability, defining the mechanisms underlying HSPG regulation of proper pathway activation. (Aim 1c). I will determine the impact of Sulf1 inhibition on dystrophic, myofiber-associated MuSC self-renewal (Aim 2a). Finally, I will evaluate the functional role of HSPG 6-O-sulfation in a preclinical model of DMD by inhibiting Sulf1 expression in (Aim 2b) transplanted, donor MuSC and (Aim 2c) native, dystrophic MuSC. Through these studies I will investigate a molecular mechanism, HSPG 6-O-sulfation, able to regulate FGF and Wnt/β-catenin signaling and MuSC regenerative potential in dystrophic animals. This work will potentially identify Sulf1 as a novel therapeutic target for the enhancement of MuSC self-renewal and the amelioration of DMD.

描述（由申请人提供）：骨骼肌的发育和修复需要肌肉干细胞（MuSC），在肌肉生长和再生的动态时期，MuSC 必须选择性地解释大量信号分子以实现自我更新。杜氏肌营养不良症 (DMD) 是一种无法治愈的破坏性肌肉萎缩疾病，其特点是微环境信号改变，对 MuSC 介导的再生潜力产生负面影响。为了了解 MuSC 如何与其细胞外环境进行通信，我探索了几种信号转导的膜结合介质，特别是多聚糖，它们在 MuSC 中高度表达，并且可以调节 HSPG 上的配体生物利用度和受体形成。通过翻译后修饰增加行为复杂性，导致关键信号通路的活性差异，因为成人的再生概括了肌生成的几个方面。我的初步研究集中在胎儿 MuSC（成人 MuSC 的发育前体）中的 HSPG 硫酸化，我已经证明 Sulf1（HSPG 6-O-硫酸化的特异性调节剂）在胎儿 MuSC 中下调。我提供了胎儿 MuSC 具有抗性的证据。体外肌源性定型，移植后能够在体内快速扩张和长期自我更新。此外，未定型的胎儿 MuSC 对强促丝裂原 FGF2 优先敏感，但反应较弱。事实上，Sulf1 先前已被证明可同时促进 Wnt/β-catenin 信号传导并抑制 FGF2 信号传导，并且 HSPG 表达在肌肉萎缩条件下失调。为了检查 HSPG 6-O-硫酸化对营养不良性 MuSC 自我更新和再生潜力的调节作用，我建议（目标 1a）验证 HSPG。为了确定 MuSC 对 FGF 和 Wnt/β-catenin 通路激活的反应（目标 1b），我将测量下游信号传导的表达和磷酸化水平。 HSPG 6-O-硫酸化的抑制将确定其在 FGF 受体复合物形成和 Wnt3a 配体生物利用度中的作用，从而确定其潜在机制。 HSPG 对适当途径激活的调节（目标 1c）。我将确定 Sulf1 抑制对营养不良的肌纤维相关 MuSC 自我更新的影响（目标 2a）。在 DMD 临床前模型中，通过抑制 (Aim 2b) 移植的供体 MuSC 和 (Aim 2c) 天然营养不良 MuSC 中的 Sulf1 表达。通过这些研究，我将研究一种分子机制，HSPG 6-O-硫酸化，能够调节营养不良动物中的 FGF 和 Wnt/β-catenin 信号传导以及 MuSC 再生潜力。这项工作将有可能将 Sulf1 确定为增强的新治疗靶点。 MuSC 自我更新和 DMD 的改善。